Seat and back rest for a chair



FIG. 1 is a perspective view showing the top, left side and front of a seat and backrest for a chair, the broken lines of other parts of the chair in this figure being for illustrative purposes only and forming no part of the claimed design;

FIG. 2 is a left side elevational view thereof;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a front elevational view; and,

FIG. 6 is a top plan view thereof.

The short broken lines shown on the seat and back rest for a chair in FIGS. 1 through 6 are understood to represent stitching. 

The ornamental design for a seat and back rest for a chair, as shown and described. 